Today there is an absence of circuit technology for use with multi-valued data elements. A multi-valued data element may encode more information, in a variety of characteristics, than a binary valued date element in which the information contained therein is necessarily limited and is represented by xe2x80x9c1""sxe2x80x9d and xe2x80x9c0""sxe2x80x9d. It is true that conventional binary technology and relating microcomputer technology can also be applied to multi-valued data, but the result is far from satisfactory.
As binary computer systems are based on the presence/absence of 1 (one), recording even a small quantity of data requires substantial recording space. For this reason, memory capacity is often found to be inadequate in compact recording media.
In contrast, the present invention provides a multi-valued recording system which enables a larger memory capacity and faster operating speed with a recording space of almost the same size as required by a conventional binary system.
This invention relates to a method of producing various kinds of memory points in a recording medium to record not only xe2x80x9c1""sxe2x80x9d but also plural values in digital or analog form. The rules for the usage and decoding of multi-valued data elements on a particular recording, direct software, and etc., are written in the same medium.
There has been no comparable method of encoding multi-valued data elements for storage in a memory point up to now, so technology and hardware components to carry out this method, such as a memory unit for recording multi-valued data elements or a personal computer to process them, have not yet been developed.
Recording space for data is one important consideration for data storage methods and equipment. At present, recording media such as magnetic tapes and disks, optical disks, and etc. have been prepared to record signals with 0""s and 1""s in the binary system. Therefore, to deal with the large amounts of data the multi-valued data element system is expected to treat, the binary recording system needs a very large amount of memory medium since the recording operation is repeated over and over again at different memory points in order to store the data in binary format. But the size of a recording medium (tape, disk, etc.) has its own limit, and consequently so does its recording space.
For example, to put into practice code transmission systems, or any other multi-valued system in the future, there can be no other choice for the time being than using large quantities of binary memory storage media (magnetic tapes, floppy disks, or optical disks, etc.), using today""s microcomputers or personal computers. However, although there is a growing need today to record large quantities of data, recording capacity of media is failing to grow proportionally. In fact, sometimes data recording becomes impossible due to a shortage of memory capacity.
For the time being, no alternative exists to recording data using the presence/absence of some quantity according to the binary system: using a hole or its absence in the case of punch tape; using a single type of recorded or erased magnetic point or optical dot in the case of conventional memories (i.e., a magnetic or floppy disk, optical disk, and etc.). However, the conventional recording system is insufficient to record a large amount of data from current sources of information. If the binary system is used, a very large quantity of memory is needed. The binary data recording system is, therefore, inherently limited and problematic.
Data recording cost is a second important consideration for data storage methods and equipment. The reduced data recording costs realized by the method of the current invention have a great influence on its marketability. While the binary system requires large quantities of magnetic tapes, disks, cards, etc., to record signals, the multi-valued data elements recording system needs relatively small quantities of recording media and their materials. So when the method according to the current invention is employed, recording costs will be reduced greatly.
In the determination of the writing/reading cost, recording density plays an important role. As the multi-valued data element recording method of this invention has high recording density by nature, the cost is inherently low.
Data recording and access speeds are a third important consideration for data storage methods and equipment. Computer systems are expected to operate at high speed. The method according to the current invention can increase the speed because of multi-valued data writing/reading.
Further, this method makes it possible to record signals in diverse tracks, i.e. multichannels, if a high recording speed is not necessarily desired.
In this way, this invention provides low cost, high density, high speed, and multichannels in data recording, as a result of using various magnetic or optical factors, making it possible to record, recognize, and read them out, and thus taking the place of the conventional recording method based on only the presence/absence of a hole, a magnetic point, or an optical dot, etc. It is also an aim of this invention to provide a simple method of memory correction.
Various kinds of multi-valued data signals can be used in recording medium according to the field of human activities in which this method is employed. The multi-valued data elements to be used are chosen at random at the recording in the particular field, and an ordinal number is given to each of them.
On the recorder""s side, to, an ordinal number is given to each of the recording multi-valued data elements, which have been chosen independently from the data storing multi-valued data elements.
Through the correspondence of the two series of the ordinal numbers, the data storing signals are recorded with recording signals. The correspondence is arranged prior to the recording.
Rules for the recording method mentioned above, such as the ordinal numbers given to signals, the correspondence between them, as well as the relating software and commands, are written in a portion of the medium in advance. By doing this, the novelty and confidence will greatly be enhanced.
The invention further relates to methods for using multi-valued data elements. Electronic signals used in conventional technology generally rely on the presence or absence of a square pulse. Due to the nature of such signals, generally only the binary notation system is used for data encoding and transmission in modern computer systems.
Unfortunately, the binary notation system requires large number of bits for encoding data. This is especially problematic for wireless data transmission.
In this regard, available frequencies for signal carriers are severely limited. For example, in the 100 MHz range, current technology can barely provide assignments up to the third decimal place. The demand for available frequencies is extremely heavy and they cannot be sufficiently allocated. So frequencies must be registered in every country with the appropriate Radio Frequency Radio Regulation bureau to protect against signal interferences.
According to traditional design, only 0.1% of available frequencies are licensed for use. This is an exceedingly scarce supply and no way equal to the demand. Therefore, radio frequency regulations allow only weak output levels. This in turn, creates a kind of interference. In addition, noise interference from automobiles and other machines during reception and transmission becomes serious.
Moreover, a single signal typically requires several cycles of carrier wave in order to be transmitted due to the larger number of bits required for encoding in binary notation. Accordingly, the effective carrier-to-signal ratio is now reaching something between 100 to 1000 times. For example, a data signal on a carrier at 10 MHZ effectively becomes a 10 KHz signal. This intensifies a tendency to seek higher frequencies.
The present invention provides methods for using multi-valued data elements, not only for data recording, but only also for general computer usage and data transmission, such as with radio waves, sound waves, optical, magnetic and other types of data transmission.
Quantities to be used to record multi-valued data elements include strength, size, shape, etc. of magnetism in case of magnetic tapes and disks, and size, shape, etc. of an optical mark in case of optical disks. By using such quantities to encode data, it has become possible for one memory point to store multiple values. In this invention, the multi-valued data elements represent data not only as 0 or 1 (as in the binary system), but as any particular value produced at a memory point by a recorder. An extractor subsequently reads out digital or analog values recorded according to this process.
It is also possible to record and extract a plurality of data blocks, each composed of one or more memory points.
In other words, this invention intends to resolve the limitations of the binary system by storing data elements based on a plurality of quantities and encoding multi-valued meaning to each of the data elements prior to the recording, and making a memory point in which one of the multi-valued data elements is recorded at a memory point.
In order to make a single memory point suitable to record multi-valued data elements, where each value has a special meaning in a particular recording, it is necessary to digitize or analogize quantities of magnetism or light, like its intensity, shape, etc., so that each of the quantities can be recorded and extracted.
The low recording cost enabled by the multi-valued data recording method of the current invention yields high marketability for the method. This invention can be applied to conventional magnetic tapes, disks, and cards as well, all of which are currently widely used and which will be used even more widely in the future.
The recording density in this invention is very high by its nature, as a single memory point can represent multi-valued data. Processing speed is also enhanced according to the method of this invention because the reading/writing head does not need to move as frequently as with the binary system. Less frequent movements are required because this method uses multi-valued data elements.
It is also possible according to this invention to combine two or more memory points together, and to record or extract them at one time. That enables this method to record signals in diverse tracks.
The present invention accordingly provides a method to satisfactorily achieve the above-mentioned purposes.